BACKGROUND:Few studies have examined pretransplant CD4 count and risk of post-kidney transplant (KT) infection in persons with HIV (PWH). METHODS:This multi-center, retrospective cohort study included adult PWH undergoing KT from 2004 to 2019. The primary outcome was infection in the first year post-KT in PWH with pretransplant CD4 < 350 cells/µL versus CD4 ≥ 350 cells/µL. Relative risk was assessed using modified Poisson modeling. Restricted mean survival time analysis was used to assess 5-year posttransplant outcomes. RESULTS:Of the 75 patients included, 27% had a pretransplant CD4 < 350 cells/µL. Those with CD4 < 350 versus CD4 ≥ 350 were more likely to be hospitalized for infection in the first year (55% versus 16%, p = 0.001). There were no significant differences in relative risk of infection in the first-year posttransplant (RR: 1.31, p = 0.053), 5-year overall survival (87.5% vs. 93%, p = 0.49) or 5-year graft loss (29.4% vs. 23.1%, p = 0.61) between groups. CONCLUSION:These findings suggest that pretransplant CD4 count alone may not reflect the true risk of post-KT infection in PWH.
BACKGROUND:The use of letermovir for cytomegalovirus prophylaxis in lung transplant recipients is increasing. Letermovir may reduce voriconazole exposure through induction of CYP-mediated metabolism. This study compared voriconazole concentrations in lung transplant recipients with and without concomitant letermovir exposure. METHODS:This single-center retrospective study evaluated lung transplant recipients on prophylactic voriconazole, stratified by letermovir use. Exclusion criteria included non-steady state concentrations, concomitant interacting medications, and extracorporeal membrane oxygenation. The primary outcome was achievement of first voriconazole concentrations meeting lower and higher target thresholds (≥ 0.5 and ≥ 1 mcg/mL). Secondary outcomes included concentration-to-dose (mg/kg/day) ratio and median first concentration (mcg/mL). RESULTS:Twenty-four patients receiving voriconazole alone contributed 46 concentrations, while 14 patients receiving concomitant letermovir contributed 30 concentrations. Fewer patients in the concomitant group achieved first voriconazole concentrations ≥ 0.5 mcg/mL (23.3% vs. 34.8%, p = 0.29) and ≥ 1 mcg/mL (3.3% vs. 21.7%, p = 0.042). The concentration-to-dose ratio (0.174 vs. 0.266 L/kg, p = 0.16) and median first concentration (0.52 vs. 0.72 mcg/mL, p = 0.19) were also lower with concomitant therapy. One definite breakthrough fungal infection occurred in the concomitant group (3.3%) compared with two probable infections in the voriconazole-only group (4.3%). Breakthrough CMV viremia occurred in 14.3% and 16.7% of patients, respectively. CONCLUSION:This is the first study evaluating the impact of concomitant letermovir on voriconazole exposure during the early posttransplant period in lung transplant recipients. Concomitant letermovir was associated with reduced attainment of target voriconazole concentrations, supporting routine therapeutic drug monitoring and consideration of empiric voriconazole dose escalation when these agents are co-administered.
BACKGROUND:Sapovirus is a calicivirus, which commonly causes acute gastroenteritis. However, in immunocompromised patients, chronic infection with diarrhea and failure to thrive has been reported. Due to sapovirus emerging as an infection of concern in our kidney transplant recipients (KTRs), we sought to describe the burden of sapovirus infection in this population. METHODS:We evaluated adult KTRs with sapovirus diagnosed by stool gastrointestinal polymerase chain reaction (PCR) at our institution. Data were collected retrospectively, and included demographics, symptom burden, treatment course, and patient outcomes. RESULTS:Nine patients met inclusion criteria. The median age was 48 years old. Symptom burden was high, with a median of six patient-reported symptoms per case. Median time from symptom onset to diagnosis was 30 days. All patients reported experiencing diarrhea, and most patients reported dehydration, fatigue, and nausea. Six patients experienced weight loss relative to baseline, and four patients experienced acute kidney injury. Two patients newly required dialysis during the follow-up period, one of these due to an episode of graft rejection with subsequent graft loss. Immunosuppression was reduced in seven cases, and nitazoxanide administered in three patients. Median time from symptom onset to symptom resolution was 45 days, however several patients had very prolonged courses, including symptom duration for over a year. CONCLUSION:Sapovirus is an emerging pathogen in KTRs and was associated with significant symptom burden and morbidity, including failure to thrive, acute kidney injury, and need for dialysis. Delays in diagnosis and limited treatment options remain barriers to improving outcomes.
BACKGROUND:While vaccination is a key strategy to mitigate the severity of coronavirus disease 2019 (COVID-19) in children, the risk factors for symptomatic, medically attended (hereon referred to as "symptomatic") COVID-19 and the impact of vaccination are not well defined among pediatric solid organ transplant recipients (PSOTR). METHODS:PSOTR aged six months through 21 years at 11 centers in the Pediatric Infectious Diseases Transplant Network (PIDTRAN) were analyzed retrospectively for symptomatic COVID-19 between July 2021 and May 2023. Using a Cox proportional hazards model, risk factors associated with COVID-19-associated hospitalization, in-hospital oxygen use, mechanical ventilation, and the impact of COVID-19 vaccination were analyzed. RESULTS:Of 1370 PSOTR, 410 (29%) had symptomatic COVID-19 infection. Among those with symptomatic infection, 115 (28%) were hospitalized, 35 required in-hospital oxygen, and three required mechanical ventilation. In the study, 45% were unvaccinated against COVID-19. Compared to unvaccinated PSOTR, incompletely vaccinated PSOTR had 56% lower hazard (95% CI 0.26, 0.72, p = 0.001) of COVID-19-associated hospitalization whereas completely vaccinated did not have a statistically significant difference in hazard of hospitalization. Receipt of at least one dose of the bivalent vaccine was also associated with 92.5% lower hazard (95% CI 0.010, 0.55, p = 0.011) of hospitalization. Risk factors for hospitalization included chronic kidney disease, underlying heart disease, neurodevelopmental delay, and lymphocytopenia. CONCLUSIONS:Most PSOTR with symptomatic COVID-19 did not require hospitalization or respiratory support. Several comorbidities and lymphocytopenia are associated with severe COVID-19 in PSOTR. COVID-19 vaccination, mostly, protected PSOTR against COVID-19-associated hospitalization, but vaccine uptake among PSOTR was low.
CMV cell-mediated immunity (CMV-CMI) testing has emerged as a promising tool to refine CMV risk stratification and inform prevention strategies in transplant recipients, while recent data assess its role in novel cellular therapies. By identifying patients with robust CMV-specific immune responses, these assays can reduce unnecessary antiviral exposure and support individualized decisions on prophylaxis and preemptive therapy. The strongest evidence comes from the solid organ transplant (SOT) setting, where immune-guided strategies can safely shorten prophylaxis duration, particularly in kidney and lung transplantation. In allogeneic hematopoietic cell transplant (HCT) recipients, CMV-CMI could also guide prophylaxis discontinuation and post-prophylaxis surveillance, although data remain more limited and its added value beyond established clinical markers unclear. In chimeric antigen receptor (CAR)-T-cell therapy recipients, CMV-CMI reaches a nadir at Week 2 post-infusion and recovers by Week 4, defining a window of increased vulnerability during which most CMV reactivation occurs. Assessment at this timepoint may help identify high-risk patients; however, the clinical impact of CMV reactivation, and as a result the need for preventive strategies, remain unclear in this setting. Importantly, the major strength of CMV-CMI lies in its consistently high negative predictive value of robust T-cell responses, while its ability to pinpoint highest-risk patients remains limited. Its widespread use is hindered by assay discordance, limited geographic access, and unproven cost-effectiveness. Despite these limitations, CMV-CMI remains the best-studied strategy for individualized CMV management; further standardization and prospective validation are needed to define its role in increasingly complex immunocompromised populations.
INTRODUCTION:People living with HIV (PLWH) have a higher incidence of end-stage renal disease (ESRD) than HIV-negative individuals and are less likely to receive a kidney transplant. We described attrition and delays across the transplant care continuum for PLWH with ESRD at the Medical University of South Carolina (MUSC) and explored factors associated with waitlisting. METHODS:Retrospective review of electronic health records of PLWH with ESRD who received care at MUSC or were referred for kidney transplantation between May 1, 2012 and December 31, 2023. Progression through the transplant continuum (referral, evaluation initiation, evaluation completion, waitlisting, and transplantation) was quantified. Multivariable time-to-event analyses was performed. RESULTS:Among 234 PLWH with ESRD, transplant referral occurred in 190 (80%), of whom 135 (71%) initiated evaluation, 75 (39%) completed evaluation, 62 (32%) were waitlisted, and 44 (23%) received a transplant. Among evaluation non-completers, outstanding testing (42%) and excessive comorbidities (15%) were the most common reasons. Median time from dialysis to referral was 510 days (IQR 139-1665), and median time from evaluation to waitlisting was 306 days (IQR 186-520). In multivariable Cox regression, peritoneal dialysis was associated with shorter time to waitlisting (HR 2.60; 95% CI 1.17-5.75; p = 0.02) and Black race trended towards longer time to waitlisting (HR 0.30; 95% CI 0.08-1.11; p = 0.07). CONCLUSIONS:Although PLWH with ESRD at MUSC progressed through the transplant continuum, substantial delays were observed. Interventions to reduce structural and logistical barriers and streamline evaluation steps may improve timely access to kidney transplantation.
BACKGROUND:People who have received kidney transplants (KTs) are at increased risk for herpes zoster (HZ). The recombinant zoster vaccine (RZV) is recommended for immunocompromised individuals based on immunogenicity data, including studies in solid organ transplant populations. However, evidence on its real-world effectiveness in transplant recipients remains limited. In South Korea, RZV became available in March 2023, providing an opportunity to assess the association between RZV vaccination and incident HZ among individuals who received KT in a retrospective cohort study. METHODS:We included all adults (≥ 18 years) who underwent KT at a single 2700-bed tertiary center in Seoul, South Korea, from January 2020 through December 2024. Vaccination status was treated as a time-varying exposure. Incidence rates and adjusted hazard ratios (aHRs) were estimated using time-dependent Cox regression. RESULTS:Among 1761 adults who received KT, 388 individuals received the RZV, while 1373 remained unvaccinated. During follow-up, HZ occurred in 78 unvaccinated individuals (5.7%), while no cases occurred in the vaccinated group over 398.3 person-years. The incidence rate of HZ was 16.4 per 1000 person-years (95% confidence interval [CI]: 13.0-20.5) in the unvaccinated group and 0 (95% CI: 0.0-9.3) in the vaccinated group. In a time-dependent Cox model with Firth penalization, RZV was associated with a lower hazard of HZ (aHR, 0.06; 95% CI: 0.00-0.43; p < 0.001). CONCLUSION:No HZ events occurred among vaccinated individuals in this cohort, a finding consistent with a protective association of RZV after KT. These findings support current recommendations for RZV use in immunocompromised populations.
BACKGROUND:Kidney transplantation from living donors (LDs) offers benefits over donation after brain death (DBD). Whether LD independently protects against infection incidence remains unclear. METHODS:We compared posttransplant infection between LD (n = 102) and DBD (n = 401) groups in a prospective observational cohort of 503 KT recipients at a tertiary-care center. Crude and adjusted associations between donor type and infection risk were assessed using propensity score (PS) modeling and multivariable Cox regression. RESULTS:Cumulative incidence rates of overall and bacterial infection were 58.6% and 43.7%, respectively. Compared to DBD recipients, LD patients had lower crude risks for overall (hazard ratio [HR]: 0.53; 95% confidence interval [CI]: 0.39-0.74; p-value < 0.001) and bacterial infection (HR: 0.59; 95% CI: 0.41-0.87; p-value = 0.007). In PS-based models, donor type was no longer significant for overall (PS-adjusted HR: 0.78; 95% CI: 0.52-1.18; p-value = 0.244) or bacterial infection (PS-adjusted HR: 0.94, 95% CI: 0.59-1.50; p-value = 0.802). Similar effect modification appeared for secondary outcomes and adjusted multivariable models. CONCLUSION:Donor type did not independently influence posttransplant infection risk after adjustment for baseline recipient factors. Lower infection incidence in LD recipients may reflect favorable recipient- and transplant-related characteristics rather than donor-specific factors.
BACKGROUND:Cytomegalovirus (CMV) remains a major cause of morbidity in solid organ transplant (SOT) recipients. While universal prophylaxis and preemptive therapy (PET) are standard strategies, comparative data in Latin American populations-characterized by high CMV seroprevalence-are limited. METHODS:We conducted a retrospective cohort study of 731 adult recipients (2016-2024). Patients were stratified into intermediate (R+) or high-risk (D+/R- or thymoglobulin induction) groups. The primary outcome was proven CMV disease at 12 months. Bias was addressed using Inverse Probability Weighting (IPW). RESULTS:Of 731 transplants, 311 were high-risk and 420 intermediate-risk. No significant difference was observed in CMV disease incidence between PET (1.9%) and prophylaxis (2.4%) (p = 0.943). IPW confirmed no association between the strategy and CMV infection (OR: 1.21; 95% CI: 0.25-5.57; p = 0.810). Notably, the absence of lymphopenia at 1 month posttransplantation was found to be protective against CMV disease (p < 0.001). CONCLUSION:Both strategies were associated with a low incidence of CMV disease. A DNAemia threshold of 4000 IU/mL for PET proved safe across all risk strata. Early absolute lymphocyte count > 1000 cells/µL is a strong predictor of protection against CMV disease.
BACKGROUND:In Switzerland, hepatitis E virus (HEV) Genotype 3 is the leading cause of acute viral hepatitis and is mainly transmitted via contaminated pork, but also through solid organ transplantation and blood transfusion. Immunocompromised patients are particularly at risk, as chronic hepatitis may develop. This nationwide cross-sectional study aimed to retrospectively assess HEV epidemiology in SOT and allogeneic hematopoietic stem cell transplant recipients. METHODS:A total of 2942 patients from the Swiss Transplant Cohort Study sampled at transplantation date (T0) and at 1-year follow-up (T12) were tested for anti-HEV IgG and HEV RNA. For seroconverted or HEV RNA-positive patients, further analyses were performed, including characterization of samples collected 6 months posttransplantation (T6). Furthermore, 587 archived blood donor samples were retrospectively examined to investigate their potential role in HEV transmission. RESULTS:The anti-HEV IgG seroprevalence of 21.6% at T0 and 19.4% at T12 in transplant recipients was comparable to that of Swiss blood donors. However, the overall incidence of HEV RNA of 1:210 was more than 20-fold higher, with 53% of infections persisting for 6 months or more. Except for one imported genotype 1g case, all infections were of Genotype 3, predominantly subtype 3h3, which is endemic in Switzerland. Notably, a transfusion-transmitted HEV infection was identified. CONCLUSION:Given the increased susceptibility of transplant recipients to HEV and their reduced ability to clear the infection, surveillance and dietary advisory measures are crucial to reduce the risk of potentially deleterious outcomes. HEV screening of blood donors should be maintained as an important preventive measure.
Transplant infectious diseases (ID) has emerged as a distinct area of clinical expertise within the specialty of ID. While formal curricular recommendations for both adult and pediatric TID have been published, there is substantial heterogeneity in how they are operationalized. In this review, we describe a practical framework and tools for building and implementing a TID curriculum and provide concrete guidance for translating high-level recommendations about content and experience into actionable strategies for training programs. This framework draws from curricular components and innovations from four US-based training programs, spanning adult and pediatric TID, and representing both dedicated TID fellowships and TID tracks within general ID training. We highlight components that would be important to any TID educational program, including key personnel, structured didactic offerings, curated external educational resources, experiential learning and professional development opportunities, and assessment tools aligned with TID-specific competencies. We provide concrete examples and adaptable tools, such as didactic schedules and self-directed curricula; guidance for leveraging podcasts, curated medical literature, and other external resources for TID education; as well as strategies to incorporate nonclinical experiential learning opportunities, such as participation in center-specific or professional society meetings, simulation-based donor call training, and protocol development. These frameworks and resources are adaptable to a range of institutional contexts, can supplement the heterogeneity in clinical exposure between programs, and support trainee competence in nonclinical skills unique to TID practice. As the field continues to evolve, scalable curricula will be essential to train the next generation of TID clinicians and educators and ensure high-quality care for an increasingly complex immunocompromised host population.
BACKGROUND:Data on deceased donor infectious diseases screening practices across the Gulf Cooperation Council (GCC) are limited, despite regional variation in transplant systems, diagnostic capacity, and cross-border organ sharing. METHODS:We conducted a cross-sectional, web-based survey from August to December 2025 among infectious diseases physicians involved in solid organ transplantation across GCC countries. The survey assessed respondent characteristics, donor screening and consultation practices, perceived barriers, proposed interventions, and free-text responses. Likert-scale items were summarized using mean ± standard deviation; free-text responses were reviewed qualitatively. RESULTS:Thirty-three infectious diseases physicians completed the survey, corresponding to an estimated response rate of 66%. Most respondents were adult infectious diseases physicians (91%). Reported practices varied: 49% reported standardized written donor-screening protocols, while infectious diseases consultation before donor acceptance occurred always in 33% and often in 30%. The highest-ranked barriers were lack of standardized regional or national guidance, insufficient infection-specific training for transplant coordinators, and absence of structured donor-derived infection reporting systems. Priority interventions included structured donor-derived infection reporting, improved rapid diagnostic capability, standardized donor screening protocols, and earlier infectious diseases involvement. Open-ended responses highlighted gaps in pending microbiology follow-up, post-procurement notification, communication, multidisciplinary donor clearance, and diagnostic workflows. CONCLUSION:This GCC-wide survey identifies perceived gaps in deceased donor infectious diseases risk assessment and highlights priorities for strengthening donor screening, communication, rapid diagnostics, coordinator training, and donor-derived infection reporting. Prospective evaluation is needed to determine whether these interventions improve donor utilization, transmission prevention, and transplant safety.
BACKGROUND:Human herpesvirus 8 (HHV8), also known as Kaposi sarcoma (KS)-associated herpesvirus, can cause severe disease in liver transplant (LT) recipients, be donor-derived, and present variably. We describe HHV8 disease post-LT. METHODS:HHV8 disease was identified post-LT in New South Wales (NSW), 2017-2024, and from systematic review. Reports were compared by suspected donor-derived infection (DDI) and disease manifestation, using chi-square and t-tests. Survival was investigated with Cox proportional hazards. RESULTS:Of 188 records, 79 publications (131 cases) were included, plus four NSW cases (n = 135). Median onset was 7 months posttransplant (IQR: 5-13), with 33% suspected DDI. After median 12 months of follow-up, 68/125 had disease remission/regression; 59/135 died (49 HHV8-related). In NSW, Case 1 was proven DDI: visceral KS, 6 months post-LT; complete remission occurred with immunosuppression modification and chemotherapy. Case 2 was probable DDI: KS, multicentric Castleman's disease, and hemophagocytic lymphohistiocytosis, 3 months post-LT; the patient died despite immunosuppression modification, hydrocortisone and rituximab. Case 3 was possible DDI: KS-herpesvirus-induced cytokine syndrome, 6 months post-LT; died despite immunosuppression modification and ganciclovir. Case 4 was unlikely DDI: visceral KS, 5 months post-LT; complete remission occurred with surgery and immunosuppression modification. Survival was worse with visceral KS and non-KS disease (aHR 5.83 and 4.32, p = 0.002). Reduced immunosuppression, mTORi, and chemotherapy improved survival (aHRs 0.53, 0.36, 0.43; p = 0.006, 0.044, and 0.030). Treatment effects diverged by KS and non-KS disease. Donor screening identified more KICS and DDI, with improved non-KS disease survival. CONCLUSION:Post-LT HHV8 disease is heterogeneous, with high mortality. Targeted treatments and possibly donor screening improve survival.
BACKGROUND:As transplantation and cellular therapy expand, so must the transplant infectious diseases (TID) workforce; yet little is known about regional or national TID work standards for the existing workforce. This survey of TID clinicians in the mid-Atlantic region seeks to outline current work standards used to define a 1.0 FTE practice. METHODS:This is a cross-sectional study evaluating the current compensation structure for TID providers, conducted July-October 2025 via REDCap survey distributed to the Mid-Atlantic Transplant Infectious Diseases Society (MATIDS). The survey consisted of 18 multiple-choice questions with ranges for quantitative answers. Data were analyzed in Excel and R and descriptive statistics were used. RESULTS:Approximately one-third of eligible members responded, the majority being from academic medical centers. At least eight regional medical groups were represented. Physicians reported a mix of RVU and time-based models for defining their work standards. For a 1.0 FTE, most reported 26-30 weeks of inpatient service in academic centers and 31-35 for all respondents. Among those with set RVU targets, most were < 2000-5000. Nearly all physicians receive subsidized cFTE support, averaging 0.6 for academic faculty and 0.7 across all practice settings. Non-billable work supporting the transplant program was ubiquitous. CONCLUSION:TID work standards are often identical to those of general ID colleagues, despite substantial differences in patient population and consultation volume/practices, as well as non-billable work for the transplant program. To fairly compensate TID work, retain physicians, and attract new specialists to this increasingly complex field, we must define work standards tailored to TID.
